Influencing factors on the demagnetization of line-start permanent magnet synchronous motor during its starting process

The irreversible demagnetization of permanent magnet due to the armature reaction during the starting process of line-start permanent magnet synchronous motor (LSPMSM) has the tremendous influence on the performance, even makes the electrical machine unable to work. This paper adopts the two-dimensional time-stepping finite element method to calculate the demagnetization of permanent magnet, and analyze the influencing factors, such as the load factor and the inertia factor, the initial rotor position, and the supply voltage amplitude. Finally, the experiment validates the creditability of the calculation results of the finite element method.